Conveyor apparatus and combined weighing apparatus

ABSTRACT

Provided is a conveyor apparatus in which weighing accuracy in a combined weighing apparatus can be improved. In this conveyor apparatus in which a radial feeder ( 30 ) controls the operation of a trough ( 31 ) such that a article supplied from the trough becomes a target supply amount, the apparatus includes: a ranging sensor ( 32 ) for detecting a height (S) of the article on the trough; a drive unit ( 33 ) for driving a trough unit with predetermined feed power (P); a supply amount acquiring part ( 93 ) for acquiring a supply amount (W) supplied from the trough ( 31 ); and a deriving part ( 94 ) for deriving a relation among the height of the article, the supply amount of the trough, and the feed power of the trough by changing the feed power from the drive unit multiple times to convey the article to the trough.

TECHNICAL FIELD

The present invention relates to a conveyor apparatus and a combinedweighing apparatus.

BACKGROUND ART

An apparatus described in Patent Literature 1 is known, for example, asa conventional combined weighing apparatus. Such a combined weighingapparatus described in Patent Literature 1 includes a plurality ofconveying means for conveying articles, a plurality of weighing meansfor weighing the articles supplied by each of the conveying means,imaging means for imaging the articles on the conveying means, an imageprocessing means for determining a transporting situation of thearticles on the conveying means on the basis of an image signal from theimaging means, a predicting means for predicting a change in a supplyamount of articles from each of the conveying means on the basis of thetransporting situation, and a controlling means for changing a controlamount of each of the conveying means to control the change in thesupply amount from each of the conveying means on the basis of thepredicted result.

CITATION LIST Patent Literature

[Patent Literature 1] PCT International Publication No. WO/1995/031702

SUMMARY OF INVENTION Technical Problem

It is a necessary to supply articles from a conveying means to aweighing means so that a supply amount supplied to the weighing meansbecomes a target supply amount to improve a weighing accuracy in acombined weighing apparatus. A conventional combined weighing apparatuspredicts whether a supply amount is increased or reduced on the basis ofa weighed result from a weighing means or a transporting situation in aconveying means. The conventional combined weighing apparatus controls asupply amount of the conveying means to become the target supply amounton the basis of this predicted result. However, the conventionalcombined weighing apparatus cannot highly accurately control the supplyamount of the conveying means to become the target supply amount becausefeed power of the conveying means is controlled only on the basis ofwhether the supply amount is increased or reduced.

The present invention is directed to providing a conveyor apparatus inwhich a weighing accuracy in a combined weighing apparatus is improved,and the combined weighing apparatus.

Solution to Problem

A conveyor apparatus according to an aspect of the present invention isa conveyor apparatus that controls an operation of a conveying unit suchthat articles supplied from the conveying unit becomes a target supplyamount, and includes: a detecting unit configured to detect a heights(S) of the article on the conveying unit; a drive unit configured todrive the conveying unit with predetermined feed power; a supply amountacquiring part configured to acquire a supply amount (W) supplied fromthe conveying unit; and a deriving part configured to change the feedpower from the drive unit multipl times to convey the article to theconveying unit, acquire the height (S) of the article and the supplyamount (W) when the different types of feed power are set, and derive arelation among the height of the article, the supply amount of theconveying unit, and the feed power of the conveying unit using theacquired height (S) of the article and the acquired supply amount (W).

In the conveyor apparatus of this constitution, the drive unit can becontrolled with optimal feed power for making a target supply amount onthe basis of the feed power that can be obtained from the relation amongthe height of the article, the supply amount of the the conveying unit,and the feed power of the the conveying unit wherein the relation isautomatically derived by the deriving part. Further, the deriving partcan automatically derive the relation among the height of the article,the supply amount of the conveying unit, and the feed power of theconveying unit even in an unknown weighing target in a new product orthe like. If this relation is used for conveyance control, the articlecan be supplied from the conveying unit to become the target supplyamount. When this conveyor apparatus is used in a combined weighingapparatus, and thereby weighing accuracy is improved, and an operatingrate is improved.

In an embodiment, the conveyor apparatus further includes a control unitconfigured to drive the drive unit with the feed power obtained from theheight detected in the detecting unit and the target supply amount inthe relation. In the conveyor apparatus of this constitution, when thecontrol unit controls the conveying unit on the basis of the relationderived by the deriving part, the article can be supplied to become thetarget supply amount. This conveyor apparatus is used in the combinedweighing apparatus, and thereby the weighing accuracy and the operatingrate are improved.

In an embodiment, the deriving part calculates a coefficient (A) and acoefficient (B) in a formula below on the basis of the height (S) andthe supply amount (W) that are acquired for each of the different typesof feed power (P) when the deriving part changes the feed power from thedrive unit multipl times to convey the article to the conveying unit.

P=A×W/S+B

In the conveyor apparatus of this constitution, the drive unit can becontrolled with the optimal feed power for achieving the target supplyamount on the basis of the feed power that can be obtained on the basisof a relation between the coefficient (A) and the coefficient (B) thatare automatically derived by the deriving part.

In an embodiment, the conveyor apparatus further includes an updatingpart configured to update the coefficient (A) and the coefficient (B) onthe basis of the height (S) and the supply amount (W) that are acquiredwhen the article is conveyed in a state in which the feed power iscontrolled to become the target supply amount. In the conveyor apparatusof this constitution, for example since the coefficients are updated toa relational expression that takes a situation upstream of the conveyorapparatus into consideration, the control for conveying the article withthe optimal feed power for achieving the target supply amount ispossible in a real machine.

In an embodiment, the deriving part calculates the coefficient (A) andthe coefficient (B) by smoothing the height (S) and the supply amount(W) with respective moving averages. In the conveyor apparatus of thisconstitution, the height (S) acquired by the detecting unit and the thesupply amount (W) acquired by the supply amount acquiring part, whichare raw data, are smoothed, and an approximate straight line that is arelational expression between the height (S) and the supply amount (W)is derived, and then a relational expression between a slope of theapproximate straight line and a strength is derived.

A combined weighing apparatus according to an aspect of the presentinvention is a combined weighing apparatus that includes: a distributionunit configured to distribute articles; a plurality of conveying unitsconfigured to convey the articles supplied from the distribution unit;and a plurality of weighing units arranged corresponding to theplurality of conveying units and configured to weigh the articlessupplied from the conveying units and controls an operation of each ofthe conveying units such that the articles supplied to the weighingunits become a target supply amount, and includes: detecting unitsconfigured to detect heights of the articles on the conveying units; astoring part configured to store relations among the heights of thearticles, supply amounts of the conveying units, and feed power of theconveying units; and a control unit configured to control the conveyingunits with the feed power obtained from the heights detected by thedetecting units and the target supply amounts in the relations.

In this combined weighing apparatus, the control unit controls theconveying units with the feed power obtained from the heights detectedby the detecting units and the target supply amounts in the relationsstored in the storing part. The relations among the heights of thearticles, supply amounts of the conveying units, and feed power of theconveying units are stored in the storing part. With this constitution,in the combined weighing apparatus, the conveying units can becontrolled with optical feed power for making the target supply amounts.Therefore, in the combined weighing apparatus, the articles can besupplied from the conveying units to the weighing units to become thetarget supply amounts. As a result, in the combined weighing apparatus,the weighing accuracy is improved.

In an embodiment, the combined weighing apparatus includes a correctingpart configured to correct the feed power on the basis of differencesbetween weighed values of the articles weighed in the weighing units andthe target supply amounts. Thereby, since the weighed values of thearticles weighed in the weighing units are actually reflected on thefeed power, the control with higher accuracy is possible.

In an embodiment, the detecting units detect the heights of the articleslocated adjacent to discharge ends of the conveying units. Thereby, thecontrol unit can detect the heights of the articles just prior to beingsupplied to the weighing hoppers, that is the articles supplied to theweighing hoppers next. For this reason, the feed power can be set moreproperly. As a result, the articles can be stably supplied to theweighing hoppers at the target supply amounts.

In an embodiment, the combined weighing apparatus includes an updatingpart configured to update the relations stored in the storing partduring operation. With this constitution, the relations of the storingpart can be updated depending on, for instance, a change in suppliedstate of the articles from the distribution table, or a change insituation such as a change in property of the article. Thereby, the feedpower of the conveying units can be controlled on the basis of theupdated information. For this reason, even when a change in conveyancesituation occurs, the articles can be stably supplied to the weighinghoppers at the target supply amounts.

In an embodiment, when the feed power is defined as P, the height isdefined as S, and the supply amount is defined as W, the feed power (P)is calculated on the basis of a formula below:

P=A×W/S+B

Here, A and B are coefficients. The above formula is used, the feedpower of the conveying units is unambiguously obtained.

In an embodiment, the supply amounts (W), the coefficient (A), and thecoefficient (B) are stored in the storing part by corresponding toshapes of the articles and/or conveying passages of the conveying units.Thereby, the control corresponding to the shapes of the articles and/orconveying passages of the conveying units is possible. For this reason,the trouble of an operator changing the setting of the coefficients orthe like in each of the shapes of the articles and/or the conveyingpassages of the conveying units can be avoided.

In an embodiment, the conveying units convey the articles depending onvibration, and the feed power is an amplitude in the conveying units.The amplitude of the vibration is changed in the conveying units thatconvey the articles depending on the vibration, and thereby the supplyamount of the articles can be controlled. Thereby, the control of thesupply amount can be performed without depending on an operationcapability.

In an embodiment, the plurality of detecting units are provided inconveying directions of the conveying units. Thereby, the heights of thearticles in multiple places can be detected. For this reason, theconveying units can be controlled on the basis of an overall state ofthe articles conveyed by the conveying units.

Advantageous Effects of Invention

According to the present invention, weighing accuracy is improved in acombined weighing apparatus.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating a combined weighing apparatusaccording to a first embodiment.

FIG. 2 is a schematic view illustrating a constitution of the combinedweighing apparatus.

FIG. 3 is a block diagram illustrating a hardware constitution of thecombined weighing apparatus.

FIG. 4 is a view illustrating the vicinity of a discharge end of aradial feeder.

FIG. 5 is a block diagram illustrating a functional constitution of aconveyance control unit.

FIG. 6 is a graph illustrating a relation between a height and a supplyamount.

FIG. 7 is a block diagram illustrating a functional constitution of acontrol unit of a combined weighing apparatus according to a secondembodiment.

FIG. 8 is a view illustrating an example of a table stored in a storageunit.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment will be described with reference to thedrawings. In the description of the drawings, the same elements aregiven the same reference sign, and duplicate descriptions thereof willbe omitted. A dimensional ratio in the drawings is not necessarilyidentical with that of the description.

First Embodiment

(Overall Constitution)

FIG. 1 is a perspective view illustrating a combined weighing apparatusaccording to a first embodiment. FIG. 2 is a schematic view illustratinga constitution of the combined weighing apparatus. FIG. 3 is a blockconstitutional diagram of the combined weighing apparatus.

A combined weighing apparatus 1 includes an article supply chute 10, adistribution table (a distribution unit) 20, a plurality of radialfeeders (conveyor apparatuses or conveying units) 30, a plurality ofpool hoppers 40, a plurality of weighing hoppers 50, a collectiondischarge chute unit 60, a timing hopper 70, and a combined weighingcontrol unit 80.

The combined weighing apparatus 1 having the above constitutionfunctions as follows. In the combined weighing apparatus 1, articles areconveyed as weighing targets of the combined weighing apparatus 1 by across feeder CF. The articles are, for instance, foodstuffs. Articlesconveyed by the cross feeder CF are placed in the article supply chute10. The articles placed in the article supply chute 10 are supplied tothe distribution table 20. The distribution table 20 conveys thearticles while distributing the articles, and supplies the articles tothe plurality of radial feeders 30 arranged around the distributiontable 20. The radial feeders 30 convey the articles, which are suppliedfrom the distribution table 20, to the pool hoppers 40 providedcorresponding to the radial feeders 30, and supply the articles to thecorresponding pool hoppers 40.

The pool hoppers 40 supply the articles to the weighing hoppers 50arranged below the pool hoppers 40. The combined weighing control unit80 performs a combined weighing calculation from weighed values of loadcells 56 (to be described below), which the weighing hoppers 50 have(weighed values of the articles in the weighing hoppers 50). Thecombined weighing control unit 80 selects a combination of articleswhich has a result of the combined weighing calculation that is closestto a target value within a predetermined allowable range. The weighinghoppers 50 included in the selected combination supply the articles tothe collection discharge chute unit 60. The collection discharge chuteunit 60 supplies the articles to the timing hopper 70. The timing hopper70 supplies the articles to, for instance, a bag making and packagingmachine or the like that is installed on a rear stage of the combinedweighing apparatus 1.

(Detailed Constitution)

Next, a constitution of the combined weighing apparatus 1 will bedescribed in detail.

(Article Supply Chute)

As illustrated in FIGS. 1 and 2, the article supply chute 10 is disposedbelow an end of the cross feeder CF that places articles in the articlesupply chute 10 (an end of a side at which the articles are placed inthe article supply chute 10). The article supply chute 10 is disposedabove the distribution table 20. The article supply chute 10 is suppliedwith articles conveyed by the cross feeder CF, and supplies the articlesto the distribution table 20.

(Distribution Table)

The distribution table 20 is a table-like member formed in a conicalshape. The distribution table 20 is supplied with articles from thecross feeder CF installed above the distribution table 20 via thearticle supply chute 10. The distribution table 20 is vibrated by, forinstance, an electromagnet (not shown) to convey the supplied articlesoutward in a radial direction while distributing the supplied articlesin a circumferential direction. The distribution table 20 suppliesarticles conveyed to a periphery thereof to the plurality of radialfeeders 30 arranged below a peripheral side of the distribution table20.

(Radial Feeders)

The combined weighing apparatus 1 has the plurality of radial feeders 30(here, 14 radial feeders). The plurality of radial feeders 30 arearranged around the distribution table 20 in an annular shape. To bespecific, the plurality of radial feeders 30 radially extend around thedistribution table 20.

The radial feeders 30 include troughs (conveying units) 31, distancemeasuring sensors (detecting units) 32, drive units 33, and a conveyancecontrol unit 90 (see FIG. 3).

The troughs 31 form conveying passages along which articles are conveyedfrom the distribution table 20 side to the pool hopper 40 side.

The drive units 33 vibrate the troughs 31 with predetermined feed powerP to convey the articles supplied from the distribution table 20 outwardin the radial direction (a direction away from the distribution table20). Each of the troughs 31 supplies the article conveyed to a peripherythereof to each of the pool hoppers 40 disposed below a peripheral sideof each of the troughs 31. The drive units 33 are, for example,electromagnets.

The distance measuring sensors 32 are disposed above the troughs 31 tocorrespond to the troughs 31. That is, in the present embodiment, thenumber of distance measuring sensors 32 is 14. The distance measuringsensors 32 are mounted on support frames 34 fixed to weighing mechanismframes F, and are located above the troughs 31.

Each of the distance measuring sensors 32 detects a distance between theranging sensor 32 and an article on the trough 31. The ranging sensor32, for example, applies a beam toward the article and receives beamsreflected by the article to obtain the distance between the rangingsensor 32 and the article. As illustrated in FIG. 4, the ranging sensor32 detects a distance from an article located in the vicinity of adischarge end of the trough 31. The vicinity of the discharge end is aposition that recedes a predetermined distance from a leading end of thetrough 31 in a conveying direction of the trough 31. As an example, thevicinity of the discharge end is a position that recedes about 30 mm to50 mm from the leading end of the trough 31. The distance measuringsensors 32 output detection signals indicating the distances from thedetected articles to the conveyance control unit 90.

As illustrated in FIG. 3, the conveyance control unit 90 is connected tothe distribution table 20, components of the radial feeders 30 such asthe distance measuring sensors 32, the drive units 33, etc., and a touchpanel 86. The touch panel 86 is a liquid crystal display (LCD) that hasboth input and output functions. The touch panel 86 functions as aninput unit and an output unit. The touch panel 86 receives inputs suchas various settings related to conveyance control. For example, thetouch panel 86 receives inputs of operation parameters such as vibrationintensities of the radial feeders 30, vibration times of the radialfeeders 30, and the like. The touch panel 86 of the present embodimentalso functions as both an input unit and an output unit in the combinedweighing control unit 80.

The conveyance control unit 90 controls the drive units 33 of the radialfeeders 30 on the basis of operation parameters such as vibrationintensities of the distribution table 20 and the radial feeders 30and/or vibration times of the radial feeders 30, which are input fromthe touch panel 86. Thereby, the conveyance control unit 90 vibrates thetroughs 31. A target supply amount TW of articles supplied from theradial feeders 30 to the weighing hoppers 50 via the pool hoppers 40 isincluded in the operation parameters. The target supply amount TW is atarget amount (a constant value) of articles to be supplied to theweighing hoppers 50 per unit of time. The target supply amount TW is setfor each article.

The conveyance control unit 90 has a central processing unit (CPU) 91and a memory 92 such as a read only memory (ROM), a random access memory(RAM), or the like.

FIG. 5 is a block diagram illustrating a functional constitution of thecontrol unit. As illustrated in FIG. 5, the conveyance control unit 90has a supply amount acquiring part 93, a deriving part 94, a storingpart 96, a feeder controlling part (a controlling part) 97, and anupdating part 98. The conveyance control unit 90 is a conceptual portionthat executes various control processes in the radial feeders. Here, thesupply amount acquiring part 93, the deriving part 94, the feedercontrolling part 97, and the updating part 98 are configured as, forinstance, software in which a program stored in a ROM is loaded on a RAMand is executed by the CPU 91.

The supply amount acquiring part 93 acquires an actually supplied supplyamount W from the corresponding trough 31. To be specific, the supplyamount acquiring part 93 acquires weighed values G from signals inputfrom the load cells 56 connected to the weighing hoppers 50 (to bedescribed below). The acquired weighed values G are sent to the derivingpart 94 as the supply amounts W.

The deriving part 94 changes the feed power P from the drive units 33multiple times and conveys the articles to the troughs 31. Thereby, thederiving part 94 derives a relation among a height S of the article, thesupply amount W of the trough 31, and the feed power P of the trough 31,that is, formula (1) below.

P=A×W/S+B   (1)

Here, the feed power P is an amplitude of vibration of the radial feeder30. When a value of the feed power P is small, the amplitude is reduced.For this reason, the supply amount of articles supplied from the radialfeeder 30 to the weighing hopper 50 (the pool hopper 40) is reduced.When the value of the feed power P is great, the amplitude is increased.For this reason, the supply amount of the articles supplied from theradial feeder 30 to the weighing hopper 50 is increased.

As illustrated in FIG. 4, the height S is a distance between a bottom 30a of the radial feeder 30 and an upper portion of an article in thevicinity of the discharge end of the radial feeder 30. The supply amountW is an amount of articles supplied from the radial feeder 30 to theweighing hopper 50 via the pool hopper 40.

In formula (1) above, “A” and “B” are coefficients, and are values setcorresponding to a shape of the radial feeder 30 and/or a type ofarticle. The deriving part 94 derives the coefficients A and B.

The deriving part 94 vibrates the trough 31 with respect to the driveunit 33 with the predetermined feed power P to convey the articlesupplied from the distribution table 20 outward in the radial direction.On this occasion, the deriving part 94 acquires the height S and theweighed value G at a given time. The height S is a value indicated bythe ranging sensor 32, and the weighed value G is a value acquired bythe supply amount acquiring part 93.

The deriving part 94 performs a smoothing process on heights S from datameasured in this way (for instance, calculates a moving average of 10sections), and obtains a smoothed height Sm. Likewise, the deriving part94 performs a smoothing process on the weighed values G (for instance,calculates a moving average of 10 sections), and obtains a smoothedweighed value Gm. The deriving part 94 derives formula (2) below, whichis an approximate straight line indicating a relation between thesmoothed height Sm and the smoothed weighed value Gm.

Gm=aSm   (2)

In formula (2) above, “a” is a slope obtained from the relation betweenthe smoothed height Sm and the smoothed weighed value Gm.

Here, according to the above formula (1), the slope a and the feed powerP have a relation of formula (3) below.

a=(1/A)P−B/A   (3)

The deriving part 94 vibrates the trough 31 with respect to the driveunit 33 with the feed power P different from a previous feed power toconvey the article. On this occasion, the deriving part 94 measures theheight S and the weighed value G at a given time, and calculates thesmoothed height Sm and the smoothed weighed value Gm. The deriving part94 derives a relation between “a,” the slope of the approximate straightline in formula (2) above, and the feed power P. That is, the derivingpart 94 derives the coefficients A and B.

The storing part 96 stores the relation among the height S of thearticle, the supply amount W of the radial feeder 30, and the feed powerP of the radial feeder 30 from the coefficients A and B derived by thederiving part 94. To be specific, the above formula (1) is stored in thestoring part 96.

The feeder controlling part 97 controls the feed power P of the radialfeeder 30. The feeder controlling part 97 controls the radial feeder 30(the drive unit 33) with the feed power P obtained from the height S ofthe article based on the distance detected by the ranging sensor 32 andthe supply amount W, which became a set target supply amount, using theabove formula (1). The feeder controlling part 97 calculates the heightS of the article on the basis of the distance indicated by the detectionsignal sent from the ranging sensor 32. To be specific, the feedercontrolling part 97 calculates the height S of the article on the basisof a difference between the distance from the bottom 30 a of the radialfeeders 30 to the ranging sensor 32 and the distance indicated by thedetection signal.

The feeder controlling part 97 substitutes the calculated height S ofthe article and the supply amount W, which became the target supplyamount, into formula (1) and calculates the feed power P. The feedercontrolling part 97 controls a continuous motion of the radial feeder 30with the calculated feed power P. That is, the feeder controlling part97 controls the motion of the radial feeder 30 during vibration.

The updating part 98 updates formula (1) stored in the storing part 96during operation. The updating part 98 is different from the derivingpart 94 in that it updates formula (1) during operation. The expression“during operation” refers to, for instance, a state in which an articleis supplied to the distribution table 20 and is conveyed by the radialfeeder 30. The updating part 98 changes the coefficients A and B, andupdates the above formula (1).

The height S of the article and the weighed value G of the load cell 56has a relation shown in formula (5) below.

G=aS   (5)

In formula (5) above, “a” is a slope obtained from the relation betweenthe height S and the weighed value G in a predetermined period. Theupdating part 98 calculates the slope a in formula (5) on the basis ofthe height S and the weighed value G obtained during operation. Theupdating part 98 calculates the slope a in at least two predeterminedperiods. The slope a and the feed power P have a relation of formula (6)below.

a=(1/A)P−B/A   (6)

The updating part 98 calculates the coefficients A and B from the feedpower P and the slope a in a current operation state. The updating part98 updates the above formula (1) using the calculated coefficients A andB.

(Pool Hoppers)

The combined weighing apparatus 1 has the same number of radial feeders30 and pool hoppers 40. As illustrated in FIG. 4, the pool hoppers 40are arranged below peripheries of the radial feeders 30 in a one-to-onecorrespondence. The pool hoppers 40 temporarily store articles suppliedfrom the radial feeders 30 arranged thereabove.

Each of the pool hoppers 40 has a PH gate 42. The PH gates 42 areprovided at lower portions of the pool hoppers 40. The PH gates 42 areopened so that the pool hoppers 40 supply the articles in the poolhoppers 40 to the weighing hoppers 50 disposed below the pool hoppers40. A link mechanism (not shown) is operated by a stepping motor 44 toopen and close each of the PH gates 42. An operation of the steppingmotor 44 is controlled by the combined weighing control unit 80 (to bedescribed below).

(Weighing Hoppers)

The combined weighing apparatus 1 has the same number of pool hoppers 40and weighing hoppers 50. The weighing hoppers 50 are arranged below thepool hoppers 40 in one-to-one correspondence. The weighing hoppers 50weigh masses of the articles supplied from the pool hoppers 40, that ismasses of the articles supplied from the radial feeders 30 via the poolhoppers 40.

Each of the weighing hoppers 50 has a WH gate 52. The WH gates 52 areprovided at lower portions of the weighing hoppers 50. The WH gates 52are opened such that the weighing hoppers 50 supply the articles in theweighing hoppers 50 to the collection discharge chute unit 60. A linkmechanism (not shown) is operated by a stepping motor 54 to open andclose the WH gates 52. An operation of the stepping motor 54 iscontrolled by the combined weighing control unit 80 (to be describedbelow).

Each of the weighing hoppers 50 has the load cell (the weighing unit) 56for weighing the article held in each of the weighing hoppers 50. Theload cell 56 is an example of a weighing mechanism. A weighed result ofthe load cell 56 is sent to a multiplexer 83 of the combined weighingcontrol unit 80 (to be described below) via an amplifier (not shown) asa weighing signal.

(Collection Discharge Chute Unit)

The collection discharge chute unit 60 is an example of a discharge pathmember. After combined weighing based on the weighed results of the loadcells 56, a combination of weighed articles selected from the weighinghoppers 50 are supplied to the collection discharge chute unit 60. Thecollection discharge chute unit 60 collects the articles supplied fromthe weighing hoppers 50 and supplies the collected articles to thetiming hopper 70.

After the combined weighing based on the weighed results of the loadcells 56, the combination of weighed articles selected from the weighinghoppers 50 are supplied to an outer chute 64. The outer chute 64collects the articles supplied from the weighing hoppers 50 and suppliesthe collected articles to the timing hopper 70.

(Timing Hopper)

The timing hopper 70 delivers the articles supplied from the collectiondischarge chute unit 60 to a rear-stage bag making and packaging machineor the like. The timing hopper 70 has a gate 72. The gate 72 is providedat a lower portion of the timing hopper 70. The gate 72 is opened suchthat the timing hopper 70 supplies the articles in the timing hopper 70to the rear-stage bag making and packaging machine or the like. A linkmechanism 74 is operated by a stepping motor 76 or the like to open andclose the gate 72. An operation of the stepping motor 76 is controlledby the combined weighing control unit 80 (to be described below).

(Combined Weighing Control Unit)

As illustrated in FIG. 3, the combined weighing control unit 80 has acentral processing unit (CPU) 81 and a memory 82 such as a read onlymemory (ROM), a random access memory (RAM), or the like. In addition,the combined weighing control unit 80 has a multiplexer 83, an A/Dconverter 84, and a digital signal processor (DSP) 85.

The multiplexer 83 selects one of weighing signals of the load cells 56according to an instruction of the DSP 85 and sends the weighing signalto the A/D converter 84. The A/D converter 84 converts the weighingsignal (an analog signal) received from the multiplexer 83 into adigital signal according to a timing signal sent from the DSP 85 andsends the digital signal to the DSP 85. The DSP 85 performs filtering onthe digital signal sent from the A/D converter 84.

The combined weighing control unit 80 is connected to the components ofthe combined weighing apparatus 1 such as the stepping motor 44, thestepping motor 54, the stepping motor 76, and the touch panel 86. Thetouch panel 86 is a liquid crystal display (LCD) that has both input andoutput functions. The touch panel 86 functions as an input unit and anoutput unit. The touch panel 86 receives inputs such as various settingsrelated to the combined weighing.

The combined weighing control unit 80 performs a combined weighingcalculation based on the weighed values of articles in the weighinghoppers 50. To be specific, first, the combined weighing control unit 80calculates a mass of an article held in each of the weighing hoppers 50using the signal filtered by the DSP 85. The combined weighing controlunit 80 performs the combined weighing calculation in which the sum ofmasses of the articles is closest to a target value within apredetermined target mass range. Further, the combined weighing controlunit 80 decides on a combination of the weighing hoppers 50 on the basisof the result of the combined weighing calculation. The combinedweighing control unit 80 controls the operations of the stepping motors54 so that the WH gates 52 of the decided weighing hoppers 50 areopened. In addition, the combined weighing control unit 80 determineswhether or not any of the weighing hoppers 50 is empty. When any of theweighing hoppers 50 is empty, the combined weighing control unit 80operates the stepping motors 44 to open the PH gates 42 of the poolhoppers 40 disposed above the weighing hoppers 50. The combined weighingcontrol unit 80 controls opening/closing of the gate 72 of the timinghopper 70.

Next, an operation of the conveyance control unit 90 will be described.For example, when a relational expression deriving mode is enabled by auser, the conveyance control unit 90 initiates operations of thedistribution table 20 and the radial feeders 30. At a time of theoperation initiation, the conveyance control unit 90 operates the radialfeeders 30 with the feed power P, which is previously set as an initialvalue.

The conveyance control unit 90 controls the drive units 33 to vibratethe troughs 31 with the predetermined feed power P. Due to this action,the conveyance control unit 90 conveys articles supplied from thedistribution table 20 outward in the radial direction. At this time, theconveyance control unit 90 measures the heights S and the weighed valuesG for a given time. The conveyance control unit 90 performs a smoothingprocess on the heights S from data measured in this way (for instance,calculates a moving average of 10 sections), and obtains the smoothedheight Sm. Similarly, the conveyance control unit 90 performs asmoothing process on the weighed values G (for instance, calculates amoving average of 10 sections), and acquires the smoothed weighed valueGm. The deriving part 94 derive the above formula (2), which is anapproximate straight line indicating a relation between the smoothedheight Sm and the smoothed weighed value Gm.

Next, the conveyance control unit 90 controls the drive units 33 tovibrate the troughs 31 with the feed power P different from the previousfeed power. At this time, the conveyance control unit 90 measures theheights S and the weighed values G for a given time, and calculates thesmoothed height Sm and the smoothed weighed value Gm. A relation betweena slope “a” of the approximate straight line in the above formula (2)and the feed power P is derived. That is, the coefficients A and B arederived. The conveyance control unit 90 stores the relational expressionindicated in the above formula (1) derived in this way in the storingpart 96.

Next, an operation of the conveyance control unit 90 when a normal mode,that is a combined weighing process, is performed will be described.When a signal for initiating an operation of the combined weighingapparatus 1 is input, the conveyance control unit 90 initiatesoperations of the distribution table 20 and the radial feeders 30. At atime of the operation initiation, the conveyance control unit 90operates the radial feeders 30 with the feed power P, which ispreviously set as an initial value.

When articles located near the discharge ends of the radial feeders 30are detected by the distance measuring sensors 32, the conveyancecontrol unit 90 receives detection signals sent from the distancemeasuring sensors 32. The conveyance control unit 90 calculates theheights S of the articles on the basis of the detection signals. Theconveyance control unit 90 inputs the calculated heights S of thearticles and the supply amount W, which is a target supply amount, intothe above formula (1), and calculates the feed power P. The conveyancecontrol unit 90 controls the radial feeders 30 with the calculated feedpower P. The conveyance control unit 90 controls the operation of eachof the radial feeders 30 according to the same process.

When the articles start to be weighed in the load cells 56 of theweighing hoppers 50, the conveyance control unit 90 updates thecoefficients A and B in the above formula (1) on the basis of theweighed values and the heights S. To be specific, the conveyance controlunit 90 receives weighing signals sent from the load cells 56 within apredetermined period. The conveyance control unit 90 calculates theslope “a” on the basis of the above formula (5) using weighed valuesindicated by the received weighing signals and the heights S of thearticles. The conveyance control unit 90 obtains the coefficients A andB from the above formula (6) using the slope “a” obtained within atleast two predetermined periods. The conveyance control unit 90 updatesthe above formula (1) with the obtained coefficients A and B.

As described above, in the combined weighing apparatus 1 according tothe first embodiment, the drive units 33 can be controlled with theoptimal feed power P for achieving the target supply amounts TW on thebasis of the feed power P that can be obtained from the relations amongthe heights S of the articles, a supply amount of the troughs 31, andthe feed power P of the troughs 31, which are automatically derived bythe deriving part 94. Further, the deriving part 94 can automaticallyderive the relations among the heights S of the articles, the supplyamount W of the troughs 31, and the feed power P of the troughs 31 evenin an unknown weighing target of a new product or the like. In thecombined weighing apparatus 1, since these relations are used forconveyance control, the target supply amount TW of articles can besupplied from the troughs 31. These radial feeders 30 are used in thecombined weighing apparatus 1 to improve weighing accuracy thereof.

In the combined weighing apparatus 1, the feeder controlling part 97controls the radial feeders 30 with the feed power P obtained from theheights S based on the detected signals detected by the distancemeasuring sensors 32 and the supply amounts W, which are the targetsupply amounts in the above formula (1) stored in the storing part 96.The above formula (1), which indicates the relations among the heights Sof the articles, the supply amount W of the radial feeders 30, and thefeed power P of the radial feeders 30, is stored in the storing part 96.With this constitution, in the combined weighing apparatus 1, the radialfeeders 30 can be controlled with the optimal feed power P for achievingthe target supply amounts. Therefore, in the combined weighing apparatus1, the target supply amount of articles can be supplied from the radialfeeders 30 to the weighing hoppers 50. As a result, in the combinedweighing apparatus 1, the weighing accuracy is improved, and anoperating rate is also improved.

FIG. 6 is a graph illustrating a relation between a height and a supplyamount. In FIG. 6, the horizontal axis indicates heights of articles onthe radial feeders 30, and the vertical axis indicates a supply amountof articles supplied to the weighing hoppers 50. Straight lines L1 to L7illustrated in FIG. 6 are regression lines (approximately straightlines) of results obtained when the radial feeders 30 are operated foronly a predetermined time in a case in which amplitudes of the radialfeeders 30 differ.

As illustrated in FIG. 6, in the combined weighing apparatus 1 of thefirst embodiment, even when amplitudes are changed, a proportionalrelation between the heights S of articles on the radial feeders 30 andthe supply amount W of articles supplied to the weighing hoppers 50 isobtained. That is, in the combined weighing apparatus 1, by detectingthe heights S of the articles on the radial feeders 30 and deciding thefeed power P depending on the heights S to control the radial feeders30, the supply amount W, which is the target supply amount, areobtained. Therefore, in the combined weighing apparatus 1, for examplein a constitution in which 14 weighing hoppers 50 are provided, since acertain amount of articles can be supplied to each of the weighinghoppers 50 in good balance, seven weighing hoppers 50 can be selected.Thereby, the number of combinations of the weighing hoppers 50 can bemaximized. As a result, in the combined weighing apparatus 1, theweighing accuracy and the operating rate are improved.

In the present embodiment, the distance measuring sensors 32 detectdistances between the distance measuring sensors 32 and articles on theradial feeders 30. The conveyance control unit 90 detects the heights Sof articles located near the discharge ends of the radial feeders 30 onthe basis of the distances. Thereby, the conveyance control unit 90 candetect the heights S of the articles just before the articles aresupplied to the weighing hoppers 50, that is the articles that will besupplied to the weighing hoppers 50 next. For this reason, the feedpower P can be more properly set. As a result, the target supply amountof articles can be stably supplied to the weighing hoppers 50 at.

In the present embodiment, the updating part 98 for updating the aboveformula (1) stored in the storing part 96 during operation is provided.With this constitution, the above formula (1) can be updated dependingon, for instance, a change in a supply state of an article from thedistribution table 20, a change in a situation such as a change in aproperty of the article, or a change in a shape of the radial feeder 30.Thereby, the feed power P of the radial feeders 30 can be controlled onthe basis of the above formula (1) which is updated. For this reason,even when a change in a conveyance situation such as a change in thesupply state from an upstream side, a change in a property (a largechip, a small chip, etc.) of the article, a flavor deposition, a changein a temperature and humidity, or the like occurs, the target supplyamount of articles can be stably supplied to the weighing hoppers 50.

In the present embodiment, when the feed power is defined as P, theheight is defined as S, and the supply amount is defined as W, the feedpower P is calculated on the basis of the above formula (1). In thecombined weighing apparatus 1, the above formula (1) is used tounambiguously obtain the feed power P of the radial feeders 30.

In the present embodiment, the radial feeders 30 convey articlesdepending on vibration. The feed power P is an amplitude in the radialfeeders 30. An amplitude of the vibration is changed in the radialfeeders 30 that convey articles depending on the vibration to controlthe supply amount of the articles. Thereby, control of the supply amountcan be performed without depending on an operation capability.

In the present embodiment, the feeder controlling part 97 controls thefeed power P of the radial feeders 30 that are continuously operated. Inthis constitution, since the feed power P of the radial feeders 30 iscontrolled in a state in which articles are continuously supplied to theweighing hoppers 50, the weighing is continuously performed. For thisreason, a drop in weighing efficiency can be suppressed.

In the above embodiment, the example in which the conveyance controlunit 90 and the combined weighing control unit 80 are separatelyprovided has been described, but the present invention is not limitedthereto. For example, the functions which the conveyance control unit 90and the combined weighing control unit 80 have may be concentrated inone control unit.

Second Embodiment

Next, a second embodiment will be described. A combined weighingapparatus 1 according to the second embodiment is different from that ofthe first embodiment in that a control unit 100 is different inconstitution from the combined weighing control unit 80 of the firstembodiment, and the conveyance control unit 90 is not provided.

FIG. 7 is a block diagram illustrating a functional constitution of thecombined weighing apparatus according to the second embodiment. Asillustrated in FIG. 7, the control unit 100 has a storing part 102, afeeder controlling part 104, an updating part 106, and a correcting part108.

The storing part 102 stores relations among heights S of articles, asupply amount W of radial feeders 30, and feed power P of the radialfeeders 30. To be specific, formula (8) below is stored in the storingpart 102.

P=A×W/S+B   (8)

The feeder controlling part 104 controls the feed power P of the radialfeeders 30. The feeder controlling part 104 controls the radial feeders30 with the feed power P obtained from the heights S of the articlesbased on the distances detected by the distance measuring sensors 32 andthe supply amounts W that art set target supply amounts using the aboveformula (8). The feeder controlling part 104 calculates the heights S ofthe articles on the basis of distances indicated by detection signalssent from the distance measuring sensors 32. To be specific, the feedercontrolling part 104 calculates the heights S of the articles on thebasis of differences between distances from bottoms 30 a of the radialfeeders 30 to the distance measuring sensors 32 and the distancesindicated by the detection signals.

The feeder controlling part 104 substitutes the above formula (8) withthe calculated heights S of the articles and the supply amount W, whichis the target supply amount, and calculates the feed power P. The feedercontrolling part 104 controls operations of the radial feeders 30continuously operated with the calculated feed power P. That is, thefeeder controlling part 104 controls the operations of the radialfeeders 30 during vibration.

The updating part 106 updates the above formula (8) stored in thestoring part 102 during operation. The expression “during operation”refers to, for instance, a state in which articles are supplied to adistribution table 20 and are conveyed by the radial feeders 30. Theupdating part 106 changes coefficients A and B, and updates the aboveformula (8).

The heights S of the articles and weighed values G of load cells 56 havea relation shown in formula (9) below.

G=aS   (9)

In the above formula (9), “a” is a slope obtained from relations betweenthe heights S and the weighed values G in a predetermined period. Theupdating part 106 calculates the slope a from the above formula (9) onthe basis of the heights S and the weighed values G obtained duringoperation. The updating part 106 calculates the slope a in at least twopredetermined periods. The slope a and the feed power P have a relationof formula (10) below.

a=(1/A)P−B/A   (10)

The updating part 106 calculates the coefficients A and B from the feedpower P and the slope a in a current operation state. The updating part106 updates the above formula (8) using the calculated coefficients Aand B.

The correcting part 108 corrects the feed power P on the basis ofdifferences between weighed values of articles weighed in the load cells56 and the target supply amount. The correcting part 108 compares theweighed values of the articles weighed in the load cells 56 and thetarget supply amount, and corrects the feed power P when a differenceexceeding a predetermined range is present between the weighed valuesand the target supply amount. The predetermined range is set dependingon the articles.

To be specific, the correcting part 108 corrects the feed power Pcalculated by the feeder controlling part 104 depending on thedifferences between the weighed values and the target supply amount. Thecorrecting part 108 reduces a value of the feed power P when the weighedvalues exceed the predetermined range and are greater than the targetsupply amount. The correcting part 108 increases the value of the feedpower P when the weighed values exceed the predetermined range and aresmaller than the target supply amount. The feeder controlling part 104controls the operations of the radial feeders 30 with the feed power Pcorrected by the correcting part 108.

Subsequently, an operation of the control unit 100 will be described.When a signal for initiating operation of the combined weighingapparatus 1 is input, the control unit 100 initiates operations of thedistribution table 20 and the radial feeders 30. At a time of theoperation initiation, the control unit 100 operates the radial feeders30 with the feed power P, which is previously set as an initial value.

When articles located near discharge ends of the radial feeders 30 aredetected by the distance measuring sensors 32, the control unit 100receives detection signals sent from the distance measuring sensors 32.The control unit 100 calculates the heights S of the articles on thebasis of the detection signals. The control unit 100 calculates the feedpower P with the heights S of the articles and the supply amount W,which is a target supply amount, using the above formula (8) stored inthe storing part 102. The control, unit 100 controls the radial feeders30 with the calculated feed power P. The control unit 100 controls theoperation of each of the radial feeders 30 according to the sameprocess.

When the articles start to be weighed in the load cells 56 of weighinghoppers 50, the control unit 100 updates the above formula (8) on thebasis of the weighed values and the heights S. To be specific, when thecontrol unit 100 receives weighing signals sent from the load cells 56within a predetermined period, the control unit 100 calculates the slope“a” on the basis of the above formula (9) using weighed values indicatedby the received weighing signals and the heights S of the articles. Thecontrol unit 100 obtains the coefficients A and B from the above formula(10) using the slope “a” obtained within at least two predeterminedperiods. The control unit 100 updates the above formula (8) with theobtained coefficients A and B.

When the weighing signals sent from the load cells 56 are received, thecontrol unit 100 obtains differences between the weighed valuesindicated by the weighing signals and the target supply amount (thesupply amount W), and corrects the feed power P of the radial feeders 30when the differences exceed a predetermined range. The control unit 100corrects the feed power P calculated by the above formula (8) dependingon the differences between the weighed values and the target supplyamount.

To be specific, for example, when the weighed values exceed thepredetermined range and are greater than the target supply amount, thecontrol unit 100 corrects the feed power P so that the value of the feedpower P is smaller than that of the calculated feed power P. Thereby,amplitudes of the radial feeders 30 controlled by the feeder controllingpart 104 are reduced, and the supply amount of articles supplied fromthe radial feeders 30 to the weighing hoppers 50 via pool hoppers 40 isreduced. When the weighed values exceed the predetermined range and aresmaller than the target supply amount, the control unit 100 corrects thefeed power P so that the value of the feed power P is greater than thatof the calculated feed power P. Thereby, the amplitudes of the radialfeeders 30 controlled by the feeder controlling part 104 are increased,and the supply amount of the articles supplied from the radial feeders30 to the pool hoppers 40 is increased.

The control unit 100 performs a combined weighing calculation based onthe weighed values of articles in the load cells 56 of the weighinghoppers 50. To be specific, first, the control unit 100 calculatesmasses of articles held in the weighing hoppers 50 using a signalfiltered by a DSP 85 and performs the combined weighing calculation inwhich the sum of the masses is closest to a target value within apredetermined target mass range. The control unit 100 decides on acombination of the weighing hoppers 50 on the basis of the result of thecombined weighing calculation, and controls operations of steppingmotors 54 such that WH gates 52 of the decided weighing hoppers 50 areopened. When any of the weighing hoppers 50 is empty, the control unit100 operates stepping motors 44 to open PH gates 42 of the pool hoppers40 disposed above the weighing hoppers 50. When articles from thedecided weighing hoppers 50 are supplied to a timing hopper 70, thecontrol unit 100 controls a stepping motor 76 so that of a gate 72 ofthe timing hopper 70 is opened.

As described above, in the combined weighing apparatus 1 according tothe second embodiment, the feeder controlling part 104 controls theradial feeders 30 with the feed power P obtained from the heights Sbased on the detected signals detected by the ranging sensor 32 and thesupply amounts W that are the target supply amounts in the above formula(8) stored in the storing part 102. The above formula (8) indicating therelations among the heights S of articles, the supply amount W of radialfeeders 30, and the feed power P of the radial feeders 30 is stored inthe storing part 102. With this constitution, in the combined weighingapparatus 1, the radial feeders 30 can be controlled with optimal feedpower P for achieving the target supply amount.

The combined weighing apparatus 1 includes the correcting part 108 forcorrecting the feed power on the basis of the differences between theweighed values of the articles weighed in the weighing hoppers 50 andthe target supply amounts of the weighing hoppers 50. Thereby, since theweighed values of the articles in the weighing hoppers 50 are actuallyreflected on the feed power P, highly accurate control is possible. As aresult, in the combined weighing apparatus 1, weighing accuracy can beimproved.

In the present embodiment, the distance measuring sensors 32 detectdistances between the distance measuring sensors 32 and articles on theradial feeders 30. The control unit 100 detects the heights S ofarticles located near the discharge ends of the radial feeders 30 on thebasis of the distances. Thereby, the control unit 100 can detect theheights S of the articles just before the articles are supplied to theweighing hoppers 50, that is the articles that will be supplied to theweighing hoppers 50 next. For this reason, the feed power P can be moreproperly set. As a result, the target supply amount of articles can bestably supplied to the weighing hoppers 50.

In the present embodiment, the updating part 106 for updating the aboveformula (8) stored in the storing part 102 during operation is provided.With this constitution, for example, the above formula (8) is updateddepending on, for instance, a change in a supply state of an articlefrom the distribution table 20, a change in a situation such as a changein a property of the article, or a change in a shape of the radialfeeder 30. Thereby, the feed power P of the radial feeders 30 can becontrolled on the basis of the above formula (8) which is updated. Forthis reason, even when a change in a conveyance situation such as achange in the supply state from an upstream side, a change in a property(a large chip, a small chip, etc.) of the article, a flavor deposition,a change in a temperature and humidity, or the like occurs, the targetsupply amount of articles can be stably supplied to the weighing hoppers50.

In the present embodiment, when the feed power is defined as P, theheight is defined as S, and the supply amount is defined as W, the feedpower P is calculated on the basis of the above formula (8). In thecombined weighing apparatus 1, the above formula (8) is used tounambiguously calculate the feed power P of the radial feeders 30.

In the present embodiment, the radial feeders 30 convey articlesdepending on vibration. The feed power P is an amplitude in the radialfeeders 30. An amplitude of the vibration is changed in the radialfeeders 30 that convey articles depending on the vibration to controlthe supply amount of the articles. Thereby, the control of the supplyamount can be performed without depending on an operation capability.

In the present embodiment, the feeder controlling part 104 controls thefeed power P of the radial feeders 30 that are continuously operated. Inthis constitution, since the feed power P of the radial feeders 30 iscontrolled in a state in which articles are continuously supplied to theweighing hoppers 50, the weighing is continuously performed. For thisreason, a drop in weighing efficiency can be suppressed.

Third Embodiment

Next, a third embodiment will be described. In a combined weighingapparatus 1 according to the third embodiment, relations among heights Sof articles, a supply amount W of radial feeders 30, and feed power P ofthe radial feeders 30 are stored in a storing part 102 of a control unit100 like in the second embodiment, but they are different from that ofthe second embodiment.

The storing part 102 stores the relations among the heights S of thearticles, the supply amount W of the radial feeders 30, and the feedpower P of the radial feeders 30. To be specific, a table T shown inFIG. 8 is stored in the storing part 102 as information. As illustratedin FIG. 8, a table T has values of the supply amount W (W1, W2, . . . ,WN), values of the heights S (S1, S2, . . . , SN) of the articles, andvalues of the feed power P (PN, PN-1, . . . , P1) corresponding to oneanother. The values of the supply amount W have a relation of W1<W2< . .. <WN. The heights S have a relation of S1<S2< . . . <SN. The values ofthe feed power P have a relation of P1<P2< . . . <PN.

In the table T shown in FIG. 8, for example when the supply amount W isdefined as “W1,” “P4” among the values of the feed power P is selectedwhen the height S of the article is “S3.” In other words, if the feedpower P is defined as “P4” when the height S of the article is “S3,” thesupply amount W is “W1.”

The feed power P stored in the storing part 102 is calculated by theabove formula (8). The table T, in which the feed power P calculatedusing the coefficients A and B of the initial values is stored, isstored in the storing part 102 as an initial table T. Each piece ofinformation of the table T can be updated (rewritten).

A feeder controlling part 104 controls the feed power P of the radialfeeders 30. The feeder controlling part 104 controls the radial feeders30 with the feed power P obtained from the heights S of the articlesbased on of the distances detected by distance measuring sensors 32 andthe supply amounts W that are set target supply amounts in the table T.The feeder controlling part 104 extracts the feed power P from theheights S of the articles and the supply amount W, which is the settarget supply amount, with reference to the table T. To be specific, forexample when the supply amount W, which is the set target supply, amountis “W1” and the calculated height S is “S3,” the feeder controlling part104 extracts “P4” as the feed power P. The feeder controlling part 104controls operations of the radial feeders 30 with the feed power Pextracted from the table T.

The updating part 106 updates the table T stored in the storing part 102during operation. The updating part 106 changes the coefficients A and Bin the above formula (1) to calculate the feed power P, and updates thetable T. The updating part 106 calculates the coefficients A and B onthe basis of the above formula (9) and (10). The updating part 106calculates the feed power P using the calculated coefficients A and Band the above formula (8), and updates the table T with the feed powerP.

The correcting part 108 corrects the feed power P extracted from thetable T as described above depending on the difference between theweighed value and the target supply amount. The correcting part 108reduces a value of the feed power P when the weighed value exceeds apredetermined range and is greater than the target supply amount. Thecorrecting part 108 increases the value of the feed power P when theweighed value exceeds the predetermined range and is smaller than thetarget supply amount. The feeder controlling part 104 controls theoperations of the radial feeders 30 with the feed power P corrected bythe correcting part 108.

As described above, in the combined weighing apparatus 1 according tothe third embodiment, the feeder controlling part 104 controls theradial feeders 30 with the feed power P obtained from the heights Sbased on of the detected signals detected by the distance measuringsensors 32 and the supply amounts W becoming the set target supplyamounts in the table T stored in the storing part 102. The table T inwhich the relations among the heights S of the articles, the supplyamounts W of the radial feeders 30, and the feed power P of the radialfeeders 30 are shown is stored in the storing part 102. With thisconstitution, in the combined weighing apparatus 1, the radial feeders30 can be controlled by optimal feed power P for making the targetsupply amounts.

The correcting part 108 may be a form in which the feed power Pextracted from the table T is corrected depending on the differencebetween the weighed value and the target supply amount, or a form inwhich the feed power P stored in the table T is corrected (updated).

The present invention is not limited to the above embodiments. Forexample, in the above embodiments, the distance measuring sensors 32acting as the detecting units have been described by way of example.However, the detecting units are not limited to the distance measuringsensors 32. The detecting units may be, for instance, cameras, or thelike.

It does not matter that the detecting units are interfaces for acquiringinformation related to the heights detected ranging devices disposedoutside. That is, the detecting units have only to have a function ofacquiring the information related to the heights of the articles. Inthis case, the detecting units themselves need not detect or measure theinformation related to the heights of the articles.

In the above embodiment, the form in which the distance measuringsensors 32 are provided corresponding to the radial feeders 30 one byone has been described by way of example. However, a plurality ofdistance measuring sensors 32 may be provided in the conveyingdirections of the radial feeders 30. Thereby, the heights of thearticles in multiple places can be detected. For this reason, the radialfeeders 30 can be controlled on the basis of an overall state of thearticles conveyed by the radial feeders 30.

In the above embodiment, the form in which the distance measuringsensors 32 are provided corresponding to the radial feeders 30 one byone has been described by way of example. However, the distancemeasuring sensors 32 may not be provided corresponding to the radialfeeders 30. For example, the distance measuring sensors 32 may beprovided for the radial feeders 30 arranged radially at an interval, forinstance, for one between the two radial feeders 30. Sometimes thesupply amount of the articles supplied from the distribution table 20does not vary considerably in the neighboring radial feeders 30.Meanwhile, a result detected by one of the distance measuring sensors 32is used as a distance from the article in the radial feeders 30 disposedat both sides of the radial feeder 30 detected by the one ranging sensor32. In this case, since the number of distance measuring sensors(detecting units) can be reduced, a cost can be reduced.

In the above embodiment, the form in which the feed power P of theradial feeders 30 is the amplitude has been described by way of example.However, the feed power P may be a vibration time of the radial feeders30. Alternatively, the feed power P may be both the amplitude and thevibration time.

In the above embodiment, the form in which the feeder controlling part104 calculates the heights S of the articles on the basis of thedetected signals detected by the distance measuring sensors 32 andobtains the feed power P using the calculated heights S has beendescribed by way of example. However, the form may be a form in whichthe feeder controlling part 104 obtains the feed power P withoutcalculating the heights S. In the case of this constitution, formula(11) below is used for the calculation of the feed power P.

P=A1×W/(L−Sp)+B1  (11)

In the above formula (11), “A1” and “B1” are coefficients. “L” is adistance from the bottom 30 a of the radial feeder 30 to the rangingsensor 32. “Sp” is a detection value (a distance between the rangingsensor 32 the article) indicated by the detecting signal of the rangingsensor 32. When receiving the detecting signal sent from the rangingsensor 32, the feeder controlling part 104 substitutes the detectionvalue Sp indicated by the detecting signal and the supply amount Wbecoming the target supply amount for the above formula (4), andcalculates the feed power P.

In addition to the above embodiment, the supply amounts W, thecoefficient A, and the coefficient B may be stored in the storing part102 by corresponding to shapes of the articles and/or the conveyingpassages of the radial feeders 30. Thereby, the control corresponding tothe shapes of the articles and/or the conveying passages of the radialfeeders 30 can be performed. For this reason, the trouble of an operatorchanging setting of the coefficients or the like in each of the shapesof the articles and/or the conveying passages of the radial feeders 30can be avoided.

In the above embodiment, the radial feeders 30 acting as the conveyingunits have been described by way of example. However, the conveyingunits may be forms in which the articles are conveyed by, for instance,rotatably driven coil units (screws) or belt conveyors. In the case ofthe coil unit, the feeder controlling part 104 controls revolutions perminute (rpm) or the like of the coil unit as the feed power. Inaddition, in the case of the belt conveyor, the feeder controlling part104 controls rpm of a roller driving a belt.

In the above embodiment, the form of the conical arrangement in whichthe combined weighing apparatus 1 includes the distribution table 20,and the radial feeders 30 are radially arranged around the distributiontable 20 has been described by way of example. However, the combinedweighing apparatus may be a form of linear arrangement in which theconveying units and the weighing units are linearly arranged side byside.

A method of controlling the radial feeders 30 in the above embodimentcan be also applied to, for instance, a cross feeder CF.

REFERENCE SIGNS LIST

1 Combined weighing apparatus

10 Article supply chute

20 Distribution table

30 Radial feeder (conveyor apparatus)

31 Trough (conveying unit)

32 Ranging sensor (detecting unit)

33 Drive unit

40 Pool hopper

50 Weighing hopper

56 Load cell

80 Combined weighing control unit

86 Touch panel

90 Conveyance control unit

93 Supply amount acquiring part

94 Deriving part

96, 102 Storing part

97, 104 Feeder controlling part

98, 106 Updating part

100 Control unit

108 Correcting part

1. A conveyor apparatus that controls an operation of a conveying unitsuch that articles supplied from the conveying unit becomes a targetsupply amount, the conveyor apparatus comprising: a detecting unitconfigured to detect a heights (S) of the article on the conveying unit;a drive unit configured to drive the conveying unit with predeterminedfeed power; a supply amount acquiring part configured to acquire asupply amount (W) supplied from the conveying unit; and a deriving partconfigured to change the feed power from the drive unit multipl times toconvey the article to the conveying unit, acquire the height (S) of thearticle and the supply amount (W) when the different types of feed powerare set, and derive a relation among the height of the article, thesupply amount of the conveying unit, and the feed power of the conveyingunit using the acquired height (S) of the article and the acquiredsupply amount (W).
 2. The conveyor apparatus according to claim 1,further comprising a control unit configured to drive the drive unitwith the feed power obtained from the height detected in the detectingunit and the target supply amount in the relation.
 3. The conveyorapparatus according to claim 1, wherein the deriving part calculates acoefficient (A) and a coefficient (B) in a formula below on the basis ofthe height (S) and the supply amount (W) that are acquired for each ofthe different types of feed power (P) when the deriving part changes thefeed power from the drive unit multipl times to convey the article tothe conveying unit.P=A×W/S+B
 4. The conveyor apparatus according to claim 3, furthercomprising an updating part configured to update the coefficient (A) andthe coefficient (B) on the basis of the height (S) and the supply amount(W) that are acquired when the article is conveyed in a state in whichthe feed power is controlled to become the target supply amount.
 5. Theconveyor apparatus according to claim 3, wherein the deriving partcalculates the coefficient (A) and the coefficient (B) by smoothing theheight (S) and the supply amount (W) with respective moving averages. 6.A combined weighing apparatus having: a distribution unit configured todistribute articles; a plurality of conveying units configured to conveythe articles supplied from the distribution unit; and a plurality ofweighing units arranged corresponding to the plurality of conveyingunits and configured to weigh the articles supplied from the conveyingunits, the combined weighing apparatus controls an operation of each ofthe conveying units such that the articles supplied to the weighingunits become a target supply amount, and comprises: detecting unitsconfigured to detect heights of the articles on the conveying units; astoring part configured to store relations among the heights of thearticles, supply amounts of the conveying units, and feed power of theconveying units; and a control unit configured to control the conveyingunits with the feed power obtained from the heights detected by thedetecting units and the target supply amounts in the relations.
 7. Thecombined weighing apparatus according to claim 6, comprising acorrecting part configured to correct the feed power on the basis ofdifferences between weighed values of the articles weighed in theweighing units and the target supply amounts.
 8. The combined weighingapparatus according to claim 6, wherein the detecting units detect theheights of the articles located adjacent to discharge ends of theconveying units.
 9. The combined weighing apparatus according to claim6, comprising an updating part configured to update the relations storedin the storing part during operation.
 10. The combined weighingapparatus according to claim 6, wherein, when the feed power is definedas P, the height is defined as S, and the supply amount is defined as W,the feed power (P) is calculated on the basis of a formula below:P=A×W/S+B where A and B are coefficients.
 11. The combined weighingapparatus according to claim 10, wherein the supply amounts (W), thecoefficient (A), and the coefficient (B) are stored in the storing partby corresponding to shapes of the articles and/or conveying passages ofthe conveying units.
 12. The combined weighing apparatus according toclaim 6, wherein: the conveying units convey the articles depending onvibration; and the feed power is an amplitude in the conveying units.13. The combined weighing apparatus according to claim 6, wherein theplurality of detecting units are provided in conveying directions of theconveying units.